code: def test_list_nested_dtype():
      dt = ListDtype(ListDtype("int32"))
      expect = ListDtype("int32")
      got = dt.element_type
      assert expect == got
  
imports: import numpy
  import pandas
  import pyarrow
  import pytest
  import cudf
  from cudf.core._compat import PANDAS_GE_150
  from cudf.core.column import ColumnBase
  from cudf.core.dtypes import CategoricalDtype, Decimal32Dtype, Decimal64Dtype, Decimal128Dtype, IntervalDtype, ListDtype, StructDtype
  from cudf.testing._utils import assert_eq
  from cudf.utils.dtypes import np_to_pa_dtype
label_desc: Use image node_id 6 for calling a global function with example usage: test_list_nested_dtype() without return types